Soils and plant samples were taken from two sites south the industrial complex at Helwan, Egypt. Plants grown on the soils of the first site were irrigated with sewage water and plants grown on soils of the second site were irrigated with industrial waste water. The samples were analyzed for Fe, Mn, Zn, Cu, Pb and Ni.
Soils were enriched with the abovementioned elements to level much higher than those of the uncontaminated ones. However, none of the elements accumulated in plants in excessive phytotoxic level. It seemed that high calcium content (weather soluble or in CaCO3 form), alkalinity of soil reaction, retention of elements by mineral and organic collides, competition between heavy metals and trace elements for the same sits of absorption and limited translocation of these elements to plant tops are all factors contributing to reducing uptake of the aforementioned elements and eliminating plant toxicities. |